# NetTCP reference

Revision 1
November 8, 2003
Andrew Ruder
Software documentation for the TCPConnecting class
NetTCP.h
NetObject
If an object was attempted to have been connected in the background, this is a placeholder for that ongoing connection. -connectNetObjectInBackground:toHost:onPort:withTimeout: will return an instance of this object. This placeholder object can be used to cancel an ongoing connection with the -abortConnection method.
Description forthcoming.
Description forthcoming.
Description forthcoming.
abortConnection
Aborts the ongoing connection. If the net object conforms to the <TCPConnecting> protocol, it will receive a [<TCPConnecting>-connectingFailed:] message with a argument of `NetclassesErrorAborted`
connectionEstablished:
aTransport
Sets up the connection placeolder. If the net object conforms to <TCPConnecting> , it will receive a [<TCPConnecting>-connectingStarted:] with the instance of TCPConnecting as an argument.
connectionLost
Cleans up the connection placeholder. This will release the transport.
dataReceived:
data
This shouldn't happen while a class is connecting, but included to conform to the <NetObject> protocol.
netObject
Returns the object that will be connected by this placeholder object.
transport
Returns the transport used by this object. Will not be the same transport given to the net object when the connection is made.
Software documentation for the TCPPort class
NetTCP.h
NetPort
TCPPort is a class that is used to bind a descriptor to a certain TCP/IP port and listen for connections. When a connection is received, it will create a class set with -setNetObject: and set it up with the new connection. When the TCPPort is dealloc'd it will close the descriptor if it had not been closed already.
Description forthcoming.
Description forthcoming.
Description forthcoming.
Description forthcoming.
close
Closes the descriptor.
connectionLost
Called when the connection is closed.
desc
Returns the low-level file descriptor for the port.
initOnHost:
aHost
onPort:
aPort
Initializes a port on aHost and binds it to port aPort. If aHost is `nil`, it will set it up on all addresses on the local machine. Using zero for aPort will use a random currently available port number. Use -port to find out where it is actually bound to.
initOnPort:
aPort
Calls -initOnHost:onPort: with a `nil` argument for the host.
newConnection
Called when a new connection occurs. Will initialize a new object of the class set with -setNetObject: with the new connection.
port
Returns the port that this TCPPort is currently bound to.
setNetObject:
aClass
Sets the class that will be initialized if a connection occurs on this port. If aClass does not implement the <NetObject> protocol, will throw a FatalNetException.
Software documentation for the TCPSystem class
NetTCP.h
Used for certain operations in the TCP/IP system. There is only one instance of this class at a time, used +sharedInstance to get this instance.
Description forthcoming.
Description forthcoming.
sharedInstance
Returns the one instance of TCPSystem currently in existence.
connectNetObject:
netObject
toHost:
aHost
onPort:
aPort
withTimeout:
aTimeout
Will connect the object netObject to host aHost on port aPort. If this connection doesn't happen in aTimeout seconds or some other error occurs, it will return `nil` and the error string and error number shall be set accordingly. Otherwise this will return netObject
connectNetObjectInBackground:
netObject
toHost:
aHost
onPort:
aPort
withTimeout:
aTimeout
Connects netObject to host aHost on the port aPort. Returns a place holder object that finishes the connection in the background. The placeholder will fail if the connection does not occur in aTimeout seconds. Returns `nil` if an error occurs and sets the error string and error number accordingly.
errorNumber
Returns the errno of the last error that occurred. If it is some other non-system error, this will be zero, but the error string shall be set accordingly.
errorString
Returns the error string of the last error that occurred.
hostFromHostOrderInteger:
ip
Returns a host from a network order 32-bit integer ip address.
hostFromNetworkOrderInteger:
ip
Returns a host from a host order 32-bit integer ip address.
hostOrderInteger:
aNumber
fromHost:
aHost
Returns a host order 32-bit integer from a host Returns `YES` on success and `NO` on failure, the result is stored in the 32-bit integer pointed to by aNumber
networkOrderInteger:
aNumber
fromHost:
aHost
Returns a network order 32-bit integer from a host Returns `YES` on success and `NO` on failure, the result is stored in the 32-bit integer pointed to by aNumber
Software documentation for the TCPTransport class
NetTCP.h
NetTransport
Handles the actual TCP/IP transfer of data. When an instance of this object is deallocated, the descriptor will be closed if not already closed.
Description forthcoming.
Description forthcoming.
Description forthcoming.
Description forthcoming.
Description forthcoming.
close
Closes the transport and makes sure there is no more incoming or outgoing data on the connection.
desc
Returns the low level file descriptor that is used internally.
initWithDesc:
aDesc
withRemoteHost:
theAddress
Initializes the transport with the file descriptor aDesc. theAddress is the host that the flie descriptor is connected to.
isDoneWriting
Returns `YES` if there is no more data to write in the buffer and `NO` if there is.
localHost
Returns a NSHost of the local side of a connection.
readData:
maxDataSize
Handles the actual reading of data from the connection. Throws an exception if an error occurs while reading data. The @"Data" key in the userInfo for these exceptions should be any NSData that could not be returned. If maxDataSize is <= 0, all possible data will be read.
remoteHost
Returns a NSHost of the remote side of a connection.
writeData:
aData
If aData is `nil`, this will physically transport the data to the connected end. Otherwise this will put the data in the buffer of data that needs to be written to the connection when next possible.
Software documentation for the TCPConnecting protocol
NetTCP.h
A class can implement this protocol, and when it is connected in the background using -connectNetObjectInBackground:toHost:onPort:withTimeout: it will receive the messages in this protocol which notify the object of certain events while being connected in the background.
connectingFailed:
aError
Tells the class implementing this protocol that the error in aError has occurred and the connection will not be established
connectingStarted:
aConnection
Tells the class implementing this protocol that the connection has begun and will be using the connection place holder aConnection
NetTCP variables

The error message used when a connection is aborted.
Could be the current error string if the error number is zero and some error has occurred. Indicates that a NSHost returned an address that was invalid.
If an error occurs and error number is zero, this could be the error string. This error occurs when some operation times out.